I'd also be using a bigger exhaust valve, 1.56" or 1.60" if it fits (even if it means reducing the intake valve).
CFM: 292" @ 90% VE, 6,000 RPM (not with the stock rods!) = 502.
For boost, multiple by the pressure ratio (1.68:1 for 10 psi) = 843 CFM. You can use the 600, but your power valves may need some tweaking - the Holley lit says dual for a V8, or 1200 CFM.
I assume when you say "ricer", you're talking about those irritating little squids with the giant red katakana decals on their fart-can Civics?
A serious Supra is 1,000 hp.
